1. Field of the Invention
The present invention relates to a developing unit providing a toner supply section to mount a toner cartridge for supplying toner and an image forming apparatus utilizing the developing unit.
2. Description of the Related Art
An image forming apparatus such as a duplicator or a printer utilizing toner of the electrophotographic system and electrostatic recording system provides a developing apparatus comprising a developing means which supplies toner on a medium and develops an electrostatic latent image formed on the medium and a developing chamber accommodating such developing means and toner to be supplied to the medium from the developing means.
Since the toner in the developing chamber is gradually reduced after use, this developing apparatus is also provided with a cartridge mounting section on which the cartridge accommodating toner therein is mounted the toner is supplied to the developing chamber via this cartridge.
Recently, in view of facilitating maintenance and replacing work of the developing apparatus (particularly, the carrier which has passed its life is considered as the object, in case 2-element developer consisting of toner and carrier is used), the developing apparatus as a whole is formed as a unit, as is described in the official gazette of the Japanese Patent Laid-Open No. 62-17763, for example. Thereby it can be mounted/dismounted to from the image forming apparatus.
However, such developing unit has been accompanied by a problem that the toner spills from the when the cartridge mounting section is opened due to vibration during transportation since transportation is carried out while the toner is accommodated within the developing chamber.